1. Field of the Invention
The present invention relates to cleaning apparatus, such as machines for washing kitchenware or laundry; and in particular to systems for automatically dispensing chemicals used by such cleaning apparatus.
2. Description of the Related Art
Commercial kitchens have equipment to clean and sanitize glassware, dishes, silverware, pot, pans and cooking utensils, which are collectively referred to as “kitchenware.” Such equipment, commonly known as a “dishwasher” or more generically as a “warewasher”, has a cabinet defining an internal chamber into which trays of kitchenware are placed for washing. A washing and rinsing assembly within the chamber has a plurality of nozzles from which water sprays onto the kitchenware being cleaned. The lower part of the cabinet forms a reservoir that collects the water which is repeatedly circulated through the nozzles by a pump during the wash cycle. Thereafter during a rinse cycle, fresh water from an external supply line is fed through the nozzles. When the rinse water flows into the reservoir, a portion of the reservoir water overflows into a drain thus replacing some of the water from the wash cycle.
At various times during the cleaning process, different chemicals are dispensed from supply containers into the warewasher. These chemicals commonly include a detergent, a rinse additive, and a sanitizer. Conventional warewashing equipment have separate receptacles into which the supply containers are placed, with each receptacle dedicated to only one type of chemical. For example, U.S. Pat. No. 6,322,242 discloses a dispensing system that has separate caps for chemical containers with supply lines running from each cap to the apparatus in which the chemicals are used. Each cap or supply line is color coded to designate the chemical that is dispensed there through. Other types of marking have been used to indicate to employees which chemical container connects to each receptacle.
Chemicals for use in automatic warewashing machines are available from many manufacturers. The same type of chemical, detergent for example, may vary in concentration depending upon the specific manufacturer and even the same manufacturer may produce the same chemical in different concentrations. A lesser amount of a more concentrated chemical is required during each operating cycle than a less concentrated version of the same chemical. Therefore the amount of a chemical to dispense into the warewasher varies depending upon the particular brand.
When switching brands of a chemical, the amount of that chemical to be dispensed during each operating cycle often has to be manually adjusted. However, only a service technician is able to make that adjustment. If the operator used the machine with a different chemical without a required adjustment, either too much chemical was used, which was costly, or too little chemical was used, which did not properly clean the kitchenware.
Therefore, a need still exists for a control system that does not require an operator to adjust the dispenser when a chemical container is changed on a cleaning machine.